chipletinterconnects

Chiplet interconnects refer to the set of electrical, physical, and protocol mechanisms that link multiple chiplets within a single package or module. Chiplets are smaller dies that perform specific functions, such as compute cores, memory, or IO. The interconnects enable communication, data coherence, and synchronized operation across dies, allowing heterogeneous integration and usage of different manufacturing processes while presenting a unified system to the outside world.

Packaging approaches for chiplet interconnects include 2.5D and 3D configurations. In 2.5D packaging, chiplets sit on a silicon or organic interposer that routes signals between dies; 3D stacking uses vertical connections such as through-silicon vias to braid dies together. Bridging techniques, such as Intel’s EMIB (Embedded Multi-Die Interconnect Bridge) and related low-profile bridges, connect chiplets without requiring a full interposer. Alternative methods include die-to-die stacking with redistribution layers and microbumps that combine multiple dies within a single package.

Standards and related interfaces are evolving to support interoperability and scalability. The Universal Chiplet Interconnect Express (UCIe) project aims to define a coherent, scalable chiplet-to-chiplet interface with common signaling, reliability, and protocol semantics. Related ecosystems include memory-centric interconnects like CXL and data-centric fabrics such as Gen-Z, which address external coherence and accelerator connectivity.

Benefits and challenges of chiplet interconnects are balanced. They can improve yields, reduce per-die cost, and enable rapid integration of heterogeneous IP and process nodes. Challenges include managing latency and bandwidth between dies, thermal and power delivery, fault isolation, and the need for robust packaging infrastructures and industry-wide standardization.

Examples of chiplet-based designs appear in contemporary CPUs and accelerators, where core chips are connected by a high-speed interconnect to form a larger, coherent system.